I can see both scenarios in the New Oxford American Dictionary; however, I am not sure if one is considered more informal than the other. Or are they both proper English?

Furthermore, if they are both legal, are they semantically equivalent, or does one have a nuance lacking in the other?

I was trying to explain the two phrases to a Russian in Russian, no less, and I began to doubt my own sanity. I found myself rehearsing both phrases over and over to see if one "seemed better" than the other.